Computational model

计算模型
  • 文章类型: Journal Article
    最初很难理解来自不熟悉的谈话者的讲话。这些困难往往会随着暴露而消散,有时在几分钟或更短的时间内。对不熟悉输入的适应性现在被认为是语音感知的基本属性,在过去的二十年中,研究在确定其特征方面取得了实质性进展。适应性语音感知的潜在机制,然而,仍然未知。过去的工作已将暴露的促进作用归因于三种定性不同的假设机制中的任何一种:(1)低水平,前语言,信号归一化,(2)语言表征的变化/选择,或(3)后感性决策的变化。这些假设的直接比较,或其组合,一直缺乏。我们描述了自适应语音感知(ASP)的通用计算框架,该框架首次实现了所有三种机制。我们演示了如何使用该框架从刺激的声学特性得出感知实验的预测。使用这种方法,我们发现,在该领域大多数研究目前采用的数据分析水平上,有影响力的实验范式的签名结果并不能区分这三种机制.这凸显了改变研究实践的必要性,以便将来的实验提供更多的信息结果。我们建议对实验范式和数据分析进行具体更改。本研究的所有数据和代码都通过OSF共享,包括本文生成的RMarkdown文档,和一个R库,实现了我们提出的模型。
    Speech from unfamiliar talkers can be difficult to comprehend initially. These difficulties tend to dissipate with exposure, sometimes within minutes or less. Adaptivity in response to unfamiliar input is now considered a fundamental property of speech perception, and research over the past two decades has made substantial progress in identifying its characteristics. The mechanisms underlying adaptive speech perception, however, remain unknown. Past work has attributed facilitatory effects of exposure to any one of three qualitatively different hypothesized mechanisms: (1) low-level, pre-linguistic, signal normalization, (2) changes in/selection of linguistic representations, or (3) changes in post-perceptual decision-making. Direct comparisons of these hypotheses, or combinations thereof, have been lacking. We describe a general computational framework for adaptive speech perception (ASP) that-for the first time-implements all three mechanisms. We demonstrate how the framework can be used to derive predictions for experiments on perception from the acoustic properties of the stimuli. Using this approach, we find that-at the level of data analysis presently employed by most studies in the field-the signature results of influential experimental paradigms do not distinguish between the three mechanisms. This highlights the need for a change in research practices, so that future experiments provide more informative results. We recommend specific changes to experimental paradigms and data analysis. All data and code for this study are shared via OSF, including the R markdown document that this article is generated from, and an R library that implements the models we present.
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  • 文章类型: Journal Article
    以前的互调(IM)研究采用了刺激的两个(或多个)时间调制,刺激的不同局部元素被不同的频率调制。已在频域中分析了主要从脑电图(EEG)获得的IM的脑活动。作为一个强大的工具,IM,它可以提供神经相互作用的直接和客观的生理测量,已经成为一种有前途的方法来破译视觉感知中的神经相互作用,并揭示潜在的不同感知加工水平。在这次审查中,我们总结了IM在视觉感知中的最新应用,详细说明IM的协议和类型,并将其效用和潜在应用扩展到多感官领域。我们建议使用IM可以部分揭示多感官信息的潜在分层处理,并有助于更深入地了解潜在的大脑动力学。
    Previous intermodulation (IM) studies have employed two (or more) temporal modulations of a stimulus, with different local elements of the stimulus being modulated by different frequencies. Brain activities of IM obtained mainly from electroencephalograms (EEG) have been analyzed in the frequency domain. As a powerful tool, IM, which can provide a direct and objective physiological measure of neural interaction, has emerged as a promising method to decipher neural interactions in visual perception, and reveal the underlying different perceptual processing levels. In this review, we summarize the recent applications of IM in visual perception, detail the protocols and types of IM, and extend its utility and potential applications to the multisensory domain. We propose that using IM could prevail in partially revealing the potential hierarchical processing of multisensory information and contribute to a deeper understanding of the underlying brain dynamics.
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  • 文章类型: Journal Article
    子宫为发育中的胎儿提供保护和营养(通过其血液供应),并在适当的时间接生婴儿,从而对每个人的生活都有重要贡献。然而,尽管这个重要的角色,这是一个调查不足的器官,我们对收缩是如何开始或协调的理解仍然存在差距。子宫是一个平滑肌器官,它的收缩功能会随着荷尔蒙的波动而发生变化,这种情况的极端例子是在怀孕和分娩期间。研究人员通常使用各种方法来研究这个器官,比如子宫肌细胞实验,组织样本,或者完整的器官,或者使用数学模型来模拟电气,机械和离子活动。子宫协调收缩的复杂性仍然是一个挑战,需要来自不同研究领域的协调解决方案。这篇综述调查了实验中使用的人类和常见动物模型之间的潜在生理学差异,以及用于评估子宫功能的实验干预措施和计算模型。我们展望了混合实验干预和建模技术的未来,这些技术可用于提高对子宫健康功能机制的理解。
    The uterus provides protection and nourishment (via its blood supply) to a developing fetus, and contracts to deliver the baby at an appropriate time, thereby having a critical contribution to the life of every human. However, despite this vital role, it is an under-investigated organ, and gaps remain in our understanding of how contractions are initiated or coordinated. The uterus is a smooth muscle organ that undergoes variations in its contractile function in response to hormonal fluctuations, the extreme instance of this being during pregnancy and labor. Researchers typically use various approaches to studying this organ, such as experiments on uterine muscle cells, tissue samples, or the intact organ, or the employment of mathematical models to simulate the electrical, mechanical and ionic activity. The complexity exhibited in the coordinated contractions of the uterus remains a challenge to understand, requiring coordinated solutions from different research fields. This review investigates differences in the underlying physiology between human and common animal models utilized in experiments, and the experimental interventions and computational models used to assess uterine function. We look to a future of hybrid experimental interventions and modeling techniques that could be employed to improve the understanding of the mechanisms enabling the healthy function of the uterus.
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  • 文章类型: Review
    目前,目前还没有普遍接受的评估microRNA-疾病关联(MDA)计算模型的策略.虽然K-fold交叉验证和案例研究似乎是必须具备的程序,K的值,评估指标,和查询疾病的选择以及其他程序的包含(例如参数敏感性测试,消融研究和计算成本报告)均根据具体情况确定,并取决于研究人员的选择。在当前的审查中,我们对29种预测MDAs的最新模型进行了综合分析.根据分析结果,我们建议一个可行的评估工作流程,将适合任何未来的模型,以促进预测性能的公平和系统的评估。
    Currently, there exist no generally accepted strategies of evaluating computational models for microRNA-disease associations (MDAs). Though K-fold cross validations and case studies seem to be must-have procedures, the value of K, the evaluation metrics, and the choice of query diseases as well as the inclusion of other procedures (such as parameter sensitivity tests, ablation studies and computational cost reports) are all determined on a case-by-case basis and depending on the researchers\' choices. In the current review, we include a comprehensive analysis on how 29 state-of-the-art models for predicting MDAs were evaluated. Based on the analytical results, we recommend a feasible evaluation workflow that would suit any future model to facilitate fair and systematic assessment of predictive performance.
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  • 文章类型: Journal Article
    自从2000年代末提出问题以来,microRNA-疾病关联(MDA)预测已经基于数据融合范例实现。整合不同的数据源可以获得更全面的研究视角,并给算法设计带来了挑战,融合数据的简洁和一致的表示。经过十多年的研究,相对简单的算法,如得分函数或单个计算层可能不再足以进一步提高预测性能。先进的模型设计近年来变得越来越频繁,特别是以合理梳理多种算法的形式,称为模型融合的过程。在当前的审查中,我们介绍了29个最新的模型,并介绍了基于模型融合和非融合的MDA预测计算模型的分类法。新的分类法在模型的算法架构中表现出显著的变化,与Chen等人2017年评论中的早期相比。此外,我们讨论了自2017年以来在克服有效MDA预测障碍方面取得的进展,并阐述了如何根据一组新模式来设计未来模型。最后,我们分析了拟议分类法中每个模型类别的优缺点,并从不同角度提出了未来的研究方向,以提高模型性能。
    Since the problem proposed in late 2000s, microRNA-disease association (MDA) predictions have been implemented based on the data fusion paradigm. Integrating diverse data sources gains a more comprehensive research perspective, and brings a challenge to algorithm design for generating accurate, concise and consistent representations of the fused data. After more than a decade of research progress, a relatively simple algorithm like the score function or a single computation layer may no longer be sufficient for further improving predictive performance. Advanced model design has become more frequent in recent years, particularly in the form of reasonably combing multiple algorithms, a process known as model fusion. In the current review, we present 29 state-of-the-art models and introduce the taxonomy of computational models for MDA prediction based on model fusion and non-fusion. The new taxonomy exhibits notable changes in the algorithmic architecture of models, compared with that of earlier ones in the 2017 review by Chen et al. Moreover, we discuss the progresses that have been made towards overcoming the obstacles to effective MDA prediction since 2017 and elaborated on how future models can be designed according to a set of new schemas. Lastly, we analysed the strengths and weaknesses of each model category in the proposed taxonomy and proposed future research directions from diverse perspectives for enhancing model performance.
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  • 文章类型: Journal Article
    L型钙电流(ICaL)在心脏电生理中起关键作用,和ICaL模型是预测药物和突变的心律失常性的重要工具。经过五十年的测量和建模,ICaL产生了几种相互竞争的理论(用数学方程式编码)。然而,新模型的引入通常没有伴随着与以前工作的数据驱动的关键比较,因此,尚不清楚哪种模型最适合任何特定应用。在这次审查中,我们描述和比较了73个已发表的哺乳动物ICaL模型,并使用模拟实验来表明它们的预测存在很大的变异性,当按物种或其他类别分组时,这不会大大减少。我们提供了60个型号的型号代码,列出主要数据源,并讨论减少竞争理论的庞大清单并最终开发ICaL的社区共识模型所需的实验和建模工作。本文分为:心血管疾病>计算模型心血管疾病>分子和细胞生理学。
    The L-type calcium current ( I CaL ) plays a critical role in cardiac electrophysiology, and models of I CaL are vital tools to predict arrhythmogenicity of drugs and mutations. Five decades of measuring and modeling I CaL have resulted in several competing theories (encoded in mathematical equations). However, the introduction of new models has not typically been accompanied by a data-driven critical comparison with previous work, so that it is unclear which model is best suited for any particular application. In this review, we describe and compare 73 published mammalian I CaL models and use simulated experiments to show that there is a large variability in their predictions, which is not substantially diminished when grouping by species or other categories. We provide model code for 60 models, list major data sources, and discuss experimental and modeling work that will be required to reduce this huge list of competing theories and ultimately develop a community consensus model of I CaL . This article is categorized under: Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Molecular and Cellular Physiology.
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  • 文章类型: Journal Article
    了解在功能预测下尿路(LUT)模型方面取得了哪些进展,确定知识差距,并从他们那里发展出一条前进的道路。
    我们调查了基本LUT组件(膀胱,尿道,及其神经控制),并对与每个组件相关的常见建模策略和理论假设进行分类。鉴于LUT功能是由这些组件的相互作用产生的,我们强调了试图模拟他们的联系,并突出显示了LUT功能的未建模方面。
    目前尚无令人满意的LUT整体模型可以预测其对疾病的反应功能,治疗,或其他扰动。特别是,LUT的神经控制缺乏基于生理学的数学描述。
    根据我们对迄今为止工作的调查,预测LUT模型的潜在路径是一种模块化的努力,其中模型最初使用可扩展和可互操作的方法由单个组织级组件构建,允许它们在通用框架中连接和测试。模块化方法将允许实现全面的LUT模型的更大目标,同时保持个人工作的可管理性,确保新模型可以直接建立在先前的研究基础上,尊重组件之间的潜在相互作用,并激励为缺失组件建模的努力。使用模块化框架并基于生理原理开发模型,创建功能预测模型是该领域准备承担的挑战。
    Understand what progress has been made toward a functionally predictive lower urinary tract (LUT) model, identify knowledge gaps, and develop from them a path forward.
    We surveyed prominent mathematical models of the basic LUT components (bladder, urethra, and their neural control) and categorized the common modeling strategies and theoretical assumptions associated with each component. Given that LUT function emerges from the interaction of these components, we emphasized attempts to model their connections, and highlighted unmodeled aspects of LUT function.
    There is currently no satisfactory model of the LUT in its entirety that can predict its function in response to disease, treatment, or other perturbations. In particular, there is a lack of physiologically based mathematical descriptions of the neural control of the LUT.
    Based on our survey of the work to date, a potential path to a predictive LUT model is a modular effort in which models are initially built of individual tissue-level components using methods that are extensible and interoperable, allowing them to be connected and tested in a common framework. A modular approach will allow the larger goal of a comprehensive LUT model to be in sight while keeping individual efforts manageable, ensure new models can straightforwardly build on prior research, respect potential interactions between components, and incentivize efforts to model absent components. Using a modular framework and developing models based on physiological principles, to create a functionally predictive model is a challenge that the field is ready to undertake.
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  • 文章类型: Journal Article
    由于不同的原因,葡萄糖代谢中的数学建模已被证明非常有用。几个模型使人们对相关的生理和病理生理方面有了更深入的了解,并促进了新的实验活动,以增加对感兴趣的生物和生理系统的了解。葡萄糖代谢模型也被证明可用于识别单个个体中具有特定生理意义的参数。这与精确诊断或治疗方面的临床应用有关。在这些基于模型的生理参数中,重要的作用在于评估胰腺β细胞的不同功能方面.本研究主要研究肠促胰岛素激素和其他已知对胰岛素分泌和β细胞功能有影响的内源性物质的数学模型,主要是氨基酸,非酯化脂肪酸,和胰高血糖素.我们发现,对于肠促胰岛素激素对β细胞的影响,有相对大量的数学模型,无论是在细胞/器官水平还是在更高的水平,全身水平。相比之下,用于评估其他胰岛素促分泌素作用的模型很少.鉴于数学建模提供的机会,我们认为,在调查领域的新模型当然是可取的。
    Mathematical modelling in glucose metabolism has proven very useful for different reasons. Several models have allowed deeper understanding of the relevant physiological and pathophysiological aspects and promoted new experimental activity to reach increased knowledge of the biological and physiological systems of interest. Glucose metabolism modelling has also proven useful to identify the parameters with specific physiological meaning in single individuals, this being relevant for clinical applications in terms of precision diagnostics or therapy. Among those model-based physiological parameters, an important role resides in those for the assessment of different functional aspects of the pancreatic beta cell. This study focuses on the mathematical models of incretin hormones and other endogenous substances with known effects on insulin secretion and beta-cell function, mainly amino acids, non-esterified fatty acids, and glucagon. We found that there is a relatively large number of mathematical models for the effects on the beta cells of incretin hormones, both at the cellular/organ level or at the higher, whole-body level. In contrast, very few models were identified for the assessment of the effect of other insulin secretagogues. Given the opportunities offered by mathematical modelling, we believe that novel models in the investigated field are certainly advisable.
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  • 文章类型: Journal Article
    Polarity-dependent orientation illusions are manifested in figures in which the impression of target orientation does not depend only on geometrical relations between the elements of the figure, but also on the relations between their luminances, that is, on luminance polarities. The best-known phenomenon belonging to this class of effects is the Münsterberg/Café Wall illusion. In this paper a considerable number of examples of this type of illusions are presented, many of which are novel variants. A two-level convolutional model of such illusions is introduced, in which the first level corresponds to the stimulus input and the second level contains units fashioned after simple cells in V1, whose spatial patterns of activity represent the model\'s reaction to the stimulus. The main finding of numerous simulations of the model is that the figures inducing illusory impressions of tilt share a common spatial pattern of neural activation, labeled \'oblique clusters\', which is absent in related non-illusory figures. Furthermore, a similar pattern is also present in simulations of figures which induce veridical impressions of tilt. The simulations suggest that the neural basis of perception of a specific degree of tilt may not be the activity of neurons tuned narrowly to that particular degree of tilt, but rather the presence of certain signature spatial patterns of activity of populations of neurons.
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  • 文章类型: Journal Article
    组织和器官再生是细胞群重新排列成具有特定功能的特定形式的动态过程。传统的组织再生利用组织移植,细胞植入,和结构化支架,以达到临床疗效。然而,组织移植方法面临着供体组织的短缺,而细胞植入可能涉及没有支持性3D基质的植入细胞的泄漏。细胞迁移,扩散,结构化支架的分化可能会破坏和阻碍人为预先设计的结构,有时涉及免疫原性反应。为了克服这个限制,已经研究了在没有结构化支架引导的情况下组织/生物体形成的自组织特性和先天再生能力。这篇综述强调了用于新组织形成的调节自组织方法的不断发展的子领域,并描述了使用不同,尖端,跨学科技术。我们总结了微工程化细胞-ECM系统和3D/4D细胞打印中细胞的定向自组织。还讨论了细胞自组织的数学模型,为组织再生中的棘手问题提供合理的指导。可以预见,未来的自组织方法集成了生物数学,微纳工程,从合成生物学开发的基因回路将继续与自组织形态发生协同工作,以增强组织和器官再生自组织过程中的合理控制。
    Tissue and organ regeneration is the dynamic process by which a population of cells rearranges into a specific form with specific functions. Traditional tissue regeneration utilizes tissue grafting, cell implantation, and structured scaffolds to achieve clinical efficacy. However, tissue grafting methods face a shortage of donor tissue, while cell implantation may involve leakage of the implanted cells without a supportive 3D matrix. Cell migration, proliferation, and differentiation in structured scaffolds may disorganize and frustrate the artificially pre-designed structures, and sometimes involve immunogenic reactions. To overcome this limitation, the self-organizing properties and innate regenerative capability of tissue/organism formation in the absence of guidance by structured scaffolds has been investigated. This review emphasizes the growing subfield of the regulated self-organizing approach for neotissue formation and describes advances in the subfield using diverse, cutting-edge, inter-disciplinarity technologies. We cohesively summarize the directed self-organization of cells in the micro-engineered cell-ECM system and 3D/4D cell printing. Mathematical modeling of cellular self-organization is also discussed for providing rational guidance to intractable problems in tissue regeneration. It is envisioned that future self-organization approaches integrating biomathematics, micro-nano engineering, and gene circuits developed from synthetic biology will continue to work in concert with self-organizing morphogenesis to enhance rational control during self-organizing in tissue and organ regeneration.
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